<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>初次修改</title>
</head>

<body>
    <button onclick="set()">aaa</button>
    <script>
        var time = 10;
        var timer;
        function set() {
            clearInterval(timer)
            timer = setInterval(function () {
                console.log(time--);
            }, 1000)
        }
        // set()
    </script>
</body>

</html>